Underfeed mechanical stoker for fire-chambers of furnaces, &amp;c.



PATENTED JULY 14, 1903.

E. W. JONES. UNDBRFEED MECHANICAL STOKBR FOR FIRE CHAMBERS 0F FURNACES,8w.

APPLICATION FILED JAN. 28. 1895.

N0 1mm.

2 SHEETS-SHEET l.

INVENTOR WITNESSES No. 733,397. PATENIED JULY 14, 1903.

E. w. JONES. UNDBRFEED MECHANICAL STOKBR FOR FIRE CHAMBERS OP FURNACES,6w.

' APPLICATION FILED 1:311:28. 1895.

NO MODEL. 2 SHBETSSHEET 2.

INVENTOR "45 wnws. Finns no. mouYno.wAsmuutou, n. c.

UNITED STATES K Patented July 14, 1903.

PATENT OFFICE.

EVAN "W. JONES, OF PORTLAND, OREGON.

SPECIFICATION forming part of Letters Patent No. 733,397, dated July 14,1903.

Application filed January 28, 1895. Serial No. 536,471. (No model.)

To (ZZZ whom it may concern.-

Be it known that I, EVAN WV. JONES, a citizen of the United States,residing at Portland, in the county of Multnomah and State of Oregon,have invented certain new and useful Improvements in UnderfeedMechanical Stokers for Fire-Chambers of Furnaces, &c.; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to improvements in underfeed mechanical stokers ofthe type patented to myself by Letters Patent of the United States, No.470,052, dated March 1, 1892.

The invention consists of the combination in a furnace of an underfeedfuel-magazine, a reciprocating plunger or ram for supplying the 'samewith fuel, and fuel agitating and lifting devices mounted in saidmagazine and adapted to be operated by the reciprocating ram, so thatthe fuel is forced upward evenly along the entire length of themagazine, and means for operating the ram.

It also consists of the combination in a furnace of an underfeedfuel-magazine, a plunger or ram for supplying fuel to the same,twyer-pipes arranged along each side of the fuel-magazine and movablyconnected to the same, so as to be-capable of longitudinal expansion,removable twyer-caps attached to the tops of said pipes and providedwith airpassages, and means for operating the ram.

It also consists of certain other novel constructions, combinations, andarrangements of parts, all of which will be hereinafter moreparticularly set forth and claimed.

In the accompanying drawings, forming part of this specification, Figure1 represents a broken central vertical longitudinal section of myinvention as applied to a boiler-furnace. Fig. 2 represents a transversevertical section of the same on the line :0 a: of Fig. 1. Fig. 3represents a transverse vertical section of my said devices on the line1 y, Fig. 1. Fig. 4 represents a broken central vertical longitudinalsection of my said invention, showing a slightly-modified arrangement ofthe twyer-pipes and their connection with the blower. Fig. 5 representsatop plan view of the same. Fig. 6 represents a vertical transversesection of the devices illustrated in Fig. 4.

A in the drawings represents afuel receiving and feeding magazine, intowhich the fuel is forced by a ram or plunger B. Said magazine is formedsubstantially, as shown in the drawings, with an air-tight bottom a andairtight upwardly and outwardlyinclined or flaring sides a, saidinclined sides being either parallel to one another or slightlydiverging from front to rear, and an upwardly and rearwardly inclinedrear wall a a are provided with flanges e at their tops to facilitatetheir connection with tWyer-pipes G, which serve the double purpose ofconducting the air to the discharging-orifices of twyer-caps c andforming a part of the side walls of the fuel-magazine when bolted, asshown, to the flanges e of said magazine, the inner walls of saidtwyer-pipes being inclined for this purpose.

The magazine A has an opening a at its front end, which opening receivesthe forward end of a plunger-cylinder B. The upper side of thisplunger-cylinder is provided with an opening d through which the fuel isdischarged into said cylinder from a feedhopper D, mounted upon the samejust above said opening.

The plunger or ram B is reciprocated by any suitable and convenientpower, either independent of or connected to the engine or boiler; but Iprefer to use a small steam-engine, as shown at A in the drawings, forthat purpose. The piston of this engine is connected to the plunger orram by piston-rod a When the ram is Withdrawn back of the opening d, aportion of the coal discharges from the feed-hopper D into the cylinderB, and as said ram moves forward this coal is forced into thefeed-magazine. The bottom of the magazine A is provided along its entirelength with a groove (0, into which is loosely fitted a bar (P, which isadapted to reciprocate longitudinally in said groove. The forward end ofthis bar is secured in any substantial manner to the under side of theplunger or ram B, but preferably, as shown in the drawings, by bolts (9.The inner end of the cylinder B The side walls is enlarged, so as tomake it approximately bell-mouthed. Through an opening in the flangethat connect-s this cylinder with the flange on the magazine 13 the bara passes before entering the groove a Along the under side of thiscylinder B is a slot Z), in which an interposed plate 1) or anenlargement on the side of thebar a for connecting the bar and plungeris adapted to slide. The object of' connecting the bar a to the underside of the plunger or ram and causing it to work below and outside ofthe cylinder B is to prevent said bar from carrying the fuel backwardduring the back stroke of the plunger or rain. The bar a is preventedfrom rising out of its slot a by plates D, which are bolted to thebottom of the magazine transversely over the top of said groove at thedesired intervals. At suitable points on bar (t are secured solidagitators orlifters D, having reversely-inclined sides. In practice whenareciprocating motion is given to the plunger B for the purpose offeeding coal into the magazine A the same motion is imparted through bara to the lifters D, and they loosen and lift the fuel from the magazineinto the fire-box above, thus preventing the packing of fuel in the rearend of the magazine. By means of these lifters the fuel is elevated andfed to the fire-box evenly along the entire length of the magazine. Itwill be seen from this construction that I can make the magazine B ofany desired length and secure to the bar (L5 a correresponding greateror less number of lifters D. These lifters are not depended upon toforce the fuel back into the magazine, their function being, simply toloosen and lift the fuel from the bottom of the magazine and distributeit evenly. Tho plunger or ram B forces the fuel into the magazine fromthe feedhopper, and the lifters D then distribute and lift the'fuel outof the said magazine and over the tops of the twyer-pipes 0 onto theside plates E.

The twyer-pipes C are two independent pipesone on each side of themagazine. They extend the whole length of the magazine, forming a partof the side walls of the same, and pass out through the boiler-front,where they are connected together by pipe (3, that leads to'any suitableblower, (not shown,) the other ends of these twyer-pipes thus being leftfree to expand and contract because of the great heat to which they aresubjected.

Said twyer-pipes are connected to the flanges of the magazine A by boltswhich pass through elongated slots a in said flanges, and thus theexpansion of said pipes is provided for.

In Figs. 4, 5, and 6 is shown a modification of the arrangement ofair-pipe connection, in

which the branch air-pipe c connecting the twyer-pipes, is located atthe rear end in the ash-pit. The forward end of the twyer-pipes in thiscase extend through the front of the furnace and are free to expand andcontract and are provided with removable covers,

whereby the accumulated ashes and dust in said pipes may be blown orremoved from the same. On the upper sides of the twyer-pipes arearranged a series of rectangular blocks or caps 0", each provided with adeep depression 0 on its upper surface. Each twyer-pipe has a partition0 between each block to strengthen and support the upper side of saidpipe and atthe same time provide a snug seat for said caps. The saidcaps have slotted openings 0 in their upper inner edges that permit airunder pressure from the inside of the twyerpipes to enter the furnace,substantially as indicated by the arrows'in Fig. 6. The object of thedepressions in the tops of the caps O is to provide a receptacle whichwill soon be filled with slag or cinder, whereby a protection isafforded for said caps against the great heat to which they aresubjected.

I have illustrated two means for securing the caps G into the tops ofthe twyer-pipes. The first of these consists in providing said caps withstaples or eyelets d and passing a rod (1 longitudinally through thetwyer-pipes under the partitions in the tops of the same and throughsaid eyelets or staples, as shown in Figs. 1 and 2. The second consistsin providing each twyer-pipe internally with a longitudinal bar or strap(i and securing said caps to said strap by bolts (1 as shown in Figs. 4and 6.

A deflecting-plate Gsupports the brickwork at the forward end of themagazine and acts as a dead-plate. Slides H (shown in dotted lines inFig. 1) are provided on the outside of each of the twyer-pipes, so as tonormally close openings h in said twyer-pipes. When these slides arewithdrawn from over the openings h, any dirt or cinders that has foundits way into the inside of the twyer-pipes can be blown or removedtherefrom. The side deadplates E extend the whole length of the furnaceand are used in some cases instead of the side grates. When thetwyer-pipes are connected to the blower in the rear, as shown in themodified form of my invention, a damper or slide J is arranged in thepipe communicating with the blower, so that the amount of air admittedto the said twyerpipes can be regulated at will. This damper or slide isoperated by a bell-crank leverj and connecting-link j in conjunctionwith an operating-rod i which passes forward to the front of thefurnace, where it is notched, as at 7' so that it may be secured at thisend in any adjusted position by said notches engaging, respectively, across-bar.

I find by experience in operating stokers of this type that in order toget the best results the fresh fuel should be discharged into thefire-box along the entire length of the same and that fresh fuel shouldconstantly replace the fuel so discharged into the fire-box. I also findthat it is an advantage where a large amount of fuel is to be burnedthat the firebox and fuel-feeding magazine be of considerable length inorder to secure a long fire,

thereby spreading the fire over a considerable space, and thus providingan ample area for the introduction of air under pressure over the greenfuel and under and through the burning fuel. Owing to the considerablelength required for the fire-box and the fuel-magazine and the fact thatthe latter is supplied with fresh fuel through an admission-opening atthe extremefront end, I find that the frictional resistance offered tothe passage of the coal along the length of the magazine tends todelivermore fuel near the front of the fire-box than at the rear, thus causingan unequal distribution of the fuel. I also find that unless someprovision is made for the expansion of the twyer-pipes under the greatheat to which they are subjected they will ultimately split or crack,and thus become useless by allowing the air to escape therefrom atpoints where such an escape is useless and even harmful, as any airintroduced into the green fuel below the tops of the twyer-pipes willcause combustion in said green fuel below the point that it is intendedthe combustion should begin.

In my construction of the twyer-pipes discharging at the top of thefuel-magazine the air issuing from said pipes is thoroughly commingledwith the gases arising from the heated green fuel in the magazine andforced through the burning mass of fuel above the magazine, and thussaid gases are thoroughly consumed and prevented from escaping and atthe same time serve to promote the combustion of the burning fuelthrough which they pass.

It must be understood that in order to get the desired results themagazine A must necessarily be long and narrow for the reason that thespace between the twyer-pipes is limited to the distance which the airundera low pressure can be forced through the burning fuel, as it isobvious that if this distance is so great that the air from the oppositetwyerpipes will not meet in the center before it reaches the top of themass of burning fuel green fuel will be forced up through the center ofthe mass of burning fuel, because it will not be provided with the airnecessary to support its combustion, and one of the principal objects ofthis invention would be defeated. For this reason Iprovide my peculiararrangement of elongated fuel-magazine with long twyer-pipes arranged onupper edges of same and means for distributing the fuel equallythroughout the whole length of said magazine and means for theintroduction of air directly over the green fuel but under and throughthe burning fuel.

I do not consider it to be broadly new with me to construct a mechanicalstoker with a .retort or fuelmagazine having twyers to which air issupplied adjacent to its upper inner edges, associating a primary feedmechanism with said retort, and providing an auxiliary feed mechanism inthe retort.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an underfeed mechanical stoker designed to force fresh fuel frombelowinto' the burning fuel, an elongated fuel magazine havingoutwardly-flared sides and rear end, and provided at the top withslotted horizontal side flanges, twyer-pipes mounted on said flanges,and connected thereto by bolts which slide in the slots thereof, areciprocating plunger or ram for supplying the same with fuel, agitatingand lifting devices mounted in said magazine and connected to theplunger or ram, and a deflecting-plate arranged above the forward end ofthe fuel-magazine, substantially as described.

2. In an underfeed mechanical stoker designed to force the fresh fuelfrom below up into the burning fuel, an elongated fuel-magazine havingoutwardly-flared sides and rear end, and provided at the top withslotted horizontal side flanges, twyer-pipes mounted on said flanges,and connected thereto by bolts which slide in the slots thereof,agitating and lifting devices mounted in said magazine, a plunger or ramfor supplying green fuel to the magazine and connected to the agitatingand lifting devices, a deflectingplate mounted above the forward end ofthe magazine and side dead-plates adapted to receive the fuel dischargedfrom the magazine, substantially as described.

In testimony whereof I hereunto affix my signature in presence of twowitnesses.

EVAN W. JONES.

Witnesses:

J. O. RUTENIC, BEATRICE SWAIN.

